Parents Friends Over For Dinner

I am here with my brother, my mother, and my father today with my parents friends over for dinner. My whole family knows I don't own any underwear what so ever. After dinner, we all went to the living room to enjoy a nice conversation and watch some tv. I sat down on the couch with my brother and father while my mom sat down on the corner chair. My parents friends sat across from us on the smaller couch. My brother turned to me with a grin and whispered in my ear to get ready. He is devious so I wasn't too sure what he was thinking. I then realized when he started shaking his leg. I felt an all too familiar feeling in my silk jogging shorts shaking because of the springs in the couch. I quickly looked down and noticed the jiggling going on. My father I guess felt the couch shaking and started shaking his legs. By now, my whole body was shaking and the sensation was getting me really aroused where I couldn't hide the movement that was happening in my shorts. I was nervous hoping that no one was seeing what was coming up. I looked up and noticed my mom looking and then I looked at my parents friends and they were looking. I must have been a show for everyone because the shaking didn't stop and I was so embarrassed by what was happening but didn't want to get up due to my now teepee in my shorts so I had to suffer the embarrassment the whole time.